Superheater and pressurized boiler



Sept. 16, 1958 G. A. REHM SUPERHEATER AND PRESSURIZED BOILER 4Sheets-Sheet 2 Filed Sept. 23, 1955 PARKER I). CARTER AT TO R NEYS Sept.16, 1958 G. A. REHM 2,852,004

Y sUPERHEATER AND PRESSURIZED BOILER Filed Sept. 25, 1955 4 Sheets-Sheets INVENTOR. GUSTAV A. REHM PARKER & CARTER ATTORNEYS Sept. 16, 1958 G.A. REHM 2,852,004

SUPERHEATER AND PRESSURIZED BOILER Filed Sept. 23, 1955 4 Sheets-Sheet 4INVENTOR.

GUSTAV A. REHM PARKER 2 CARTER ATTORNEYS SUPERHEATER AND PRESSURIZEDBOILER Gustav A. Rehm, Springfield, Ill., assignor to Springfield BoilerCo., Springfield, Illa, a corporation of Illinois Application September23, 1955, Serial No. 536,081

6 Claims. (6!. 122-476) This invention is in the field of steam boilersand the like and takes the form of a new and improved boiler structurewith a superheater constructed and arranged to provide superheated steammore etficiently for a suitable industrial use or otherwise.

A primary object of my invention is a new and improved boiler structurewith a divided superheater structime Another object is a boiler having acombustion chamber, superheater space and gas path arranged in a moreefficient manner relative to each other.

Another object is a boiler of the above type having a superheaterdivided into sections with means for directing the hot gases from thecombustion space into the superheater sections at right angles to bothsets of superheater tubes therein.

Another object is a new and improved boiler structure having a platenwall directing the hot gases from the combustion space in an optimumdirection for heat transfer to a high and low temperature superheaterstructure.

Another object is a superheater structure of a new and improved type foruse in a boiler or the like.

Other objects will appear from time to time in the ensuing specificationand drawings in which:

Figure l is a plan view, in section, showing my invention;

Figure 2 is a section taken along line 22 of Figure 1;

Figure 3 is a section taken along line 33 of Figure 2;

and

Figure 4 is a section taken along line 44 of Figure 1.

In the drawings I have shown a boiler housing indicated generally atwhich includes a suitable foundation or base 12, front and rear walls14- and 16, right and left side walls 18 and 20, a roof 22, and anintermediate wall 24 extending longitudinally from the front wall withinthe housing and terminating at 26 in spaced relationship to the rearwall 16 so as to define a combustion space 28 and a gas path 39 leadingto a suitable outlet 32. Heat may be supplied to the combustion space byany suitable heating means 34 which could take the form of a gas or oilinjector, coal stoker or a unit designed for pulverized fuel with thenecessary hoppers.

A superheater space 36 occupies the entire rear portion of the housingfrom the end 26 of the intermediate wall rearwardly and is partiallymasked by a platen wall 38 which extends laterally from the end of theintermediate wall toward the side wall 18. The platen wall defines aninlet passage 49 to the superheater space on one side and an outletpassage 42 on the other side leading to the gas path. As shown in Figure1 the platen wall is approximately one third the lateral width of theinner housing and is positioned generally in the middle of the housingwith the inlet and outlet spaces or passages on each side beinggenerally equal in lateral width.

The walls of the housing are lined with the usual water wall tubes 44with a double row 46 into the back wall, and a plurality of the usualconvection tubes 48 extends through the gas path and connect the usualupper and Patented Sept. 16, 1958 lower drums 50 and 52. The platen wallis lined on each side with bafiie tubes 54 extending between the upperand lower drums, and a line of generally equally spaced screen tubes 56extend laterally from the end of the platen wall across the superheaterinlet.

The superheater tubes in the superheater space are divided into a lowtemperature superheater 58 next to the hot gas outlet and a hightemperature superheater 60 behind the inlet 40 from the combustionspace. The low temperature superheater is composed of a double 'row oftubes generally smaller in diameter than the convection and water walltubes and connected to the upper drum at 62 in Figure 3. The smallertubes bend through a tortuous path having an overall rectangularappearance and lead out through a port or opening in the side wall at 64to a primary superheater header 66. This header may be a continuous tubeor pipe bent generally at a right angle at 68 in Figure 1 and extendingalong the back wall as a secondary superheater header 70, the primaryand secondary superheater headers being separated by a suitable orificeplate '72.

The high temperature superheater 60 is connected to the secondarysuperheater header at 74 and extends through a suitable opening or portin the rear wall upwardly in an individual tortuous path but overallrectangular pattern 76 to a suspension point 78 and returns by straightsections 8% and 82 to an outlet header 84 in the rear wall below thesecondary header 76. This high temperature superheater, like the lowtemperature superheater, is composed of smaller diameter tubes, inpairs, generally parallel to each other at all points. The L-shapedheaders as and and the outlet header 84 are positioned in a box 36attached to the sides of the housing walls so that the headings can beremoved and replaced easily.

In general, each of the superheaters is composed of a plurality ofoutwardly extending tubes connected between headers, the tubes beingsmaller in diameter than the water wall and convection tubes andgenerally arranged in pairs in a plane at right angles to the headers.The tubes of high temperature superheater are generally parallel to theinflowing hot gases from the combustion space, as shown in Figure 1, somaximum heat transfer will be aifected, and the low temperaturesuperheater tubes are disposed at right angles to the high temperaturetubes so that when the hot gases turn the corner around the platen wall38 they will flow directly over the low temperature tubes.

The two sets of superheater tubes may be separated by a longitudinal rowof screen tubes 88, and the outlet from the superheater space may have asuitable row of lateral screen tubes 90.

An attemperator or heat exchanger 92 in the lower drum draws superheatedsteam from the header 66 by a suitable connection 5% which enters thelower drum 96 in Figure 2. The attemperator extends through the lowerdrum to an outlet 98 and through a connection 1% to the secondarysuperheater header 7i) beyond the orifice plate 72. Superheated steamfrom the low temperature superheater header will be drawn through theheat exchanger in the lower drum where it is cooled down to nearsaturation temperature. This part of total steam is returned into thehigh temperature superheater header 100 where it is mixed with the steampassing through the orifice plate 72. All of the steam leaving the upperdrum goes through the low temperature superheater, and part of it willbe directed down through, the heat exchanger in the lower drum andbrought back to the inlet header of the secondary superheater header Thepressure drop created between the low and:

high temperatures superheaters necessary to force some of the steamthrough the attemperator or heat exchanger is caused by the orificeplate. The steam returning from the attemperator or heat exchanger mixeswith the other portionof the steam so that all of the steam againventers'the high temperature superheater, and the temperature can becontrolled by the amount of steam going through the attemperator or heatexchanger. This functions as a steam temperature control and the orificeplate could be suitable valves or the like.

The use, operation and function of my invention are as follows:

In my invention, I have a boiler structure composed of three primaryspaces, a combustion space or chamber, a superheater space, and a gaspath leading to a suitable outlet. The housing is generally rectangularas shown in Figure 1. But the combustion space and gas path are disposedlaterally side by side, and the superheater space occupies the entirerear portion of the housing so that the hot gas from the combustionspace turns 180 through the superheater space while flowing to the gaspath. The gas path from the superheater space to outlet is baflled todirect the gases vertically up and down, thus striking all boilerconvection heating surfaces at low and high loads. In Figure 2 I haveonly shown these bafiles generally as any suitable arrangement could beused.

The platen wall extending outwardly from the end of the intermediatewall directs the gases to the inlet passage or opening for thesuperheater so that the hot gases will enter flowing in a directionparallel to a high temperature superheater disposed in the first part ofthe superheater space. The gases turn 90 while passing through thisfirst part of the superheater space, until they are flowing laterallyinto the second part of the space in which a low temperature superheateris positioned so that the gases are flowing in a rotary motion over thelow temperature tubes. Screen tubes may be laterally disposed across thesuperheater inlet and outlet, and a row of screen tubes may be usedbetween the superheater sections.

An L-shaped superheater header extends across the rear wall and part ofone side wall and functions as the outlet header for the lowtemperature: superheater and the inlet header for the high temperaturesuperheater. This L-shaped header is divided by an orifice plate intotwo sections corresponding to the two superheaters although a valvecould be used.

Both of the superheaters are composed of parallel tubes generally inpairs havinga smaller diameter than the convection and water wall tubes,and the two superheatersections are disposed at right angles to eachother so that the gas will be flowing generally parallel to the tubes ineach .section.

The platen wall defining the inlet opening to the superheater spaceextends to the edge of the high temperature superheater thus forming agas opening generally the same width as the superheater, and the hotgases enter the second or low temperature superheater at right angles totheir previous path.

It should be noted that for both superheaters a maximum heat transferwill be effected because the hot gases will be. executing a turning orrotary movement while passing over the superheating elements.

The detail of the drums have been eliminated from the figures forclarity. Likewise soot blowers, safety valves, vents, observation portand other standard items and equipment could be used but have not beenshown.

While I have shown and described the preferred form of my invention, itshould be understood that numerous modifications, substitutions,alterations and changes can bernade, and I therefore wish that myinvention be unrestricted except as bythe appended claims.

I claim:

1. In a boiler structure a housing having front, rear, and side walls,means defining a combustion space and gas path in the housing and asuperheater space between them, the combustion space and gas path beinggenerally parallel and disposed longitudinally, the superheater spacebeing laterally disposed against the rear wall across the entire rearportion of the housing, and a superheater in the superheater spaceincluding a low temperature superheater in the side of the superheaterspace adjacent and aligned with the gas path and a high temperaturesuperheater in the other side of the superheater space adjacent andaligned with the combustion space, the outlet for the low temperaturesuperheater and the inlet for the high temperature superheater beingconnected by an L-shaped header on the back Wall and side wall, the lowtemperature superheater outlet and high temperature superheater inletdividing the header into a. low temperature header portion and a hightemperature header portion, a, suitable constriction between the twoportions,- and means for regulating the temperature of the steam in thehigh temperature superheater including means for drawing off a quantityof steam in the low temperature portion of the header, cooling it, andreturning itby bypassing the constriction to the high temperatureportion of the header.

2. In a boiler structure, a housing having front, rear. and side walls,means defining a combustion space andgas path, in the housing and asuperheater space between them, the combustion space and gas path beinggenerally parallel and disposed longitudinally, the superheater spacebeing laterally disposed against the rear wall across the entire rearportion of the housing, and a superheater in the superheater spaceincluding a low temperature superheater in the side of the superheater,space adjacent and aligned with the gas path and a, high temperaturesuperheater in the other side of the super,- heater space adjacent andaligned with the combustion space, and an L-shaped generallyhorizontally disposed header connected at spaced locations to both thelow and high temperature superheaters constituting the outlet for theformer and the inlet for the latter having one leg of the Llongitudinally disposed along the side wall and the other leg laterallydisposed along the rear wall, the low temperature superheater beingconnected to the longitudinal leg and the high temperature superheaterto the lateral leg.

3. The structure of claim 2 further characterized in that the L-shapedheader has both its longitudinal and lateral legs disposed removably inopenings in the, side.-

and rear walls, respectively.

4. The structure of claim 1 further characterized in;

between them which terminates a substantial distance.-

from the rear wall of the housing, an opening in the side and rearwalls, means in the housing defining a superheater space at the end ofthe longitudinal wall to the rear wall and between the side walls, asuperheater structure in the superheater space including an L-shapedheader disposed in said opening in the sideand rear walls so as to beremovable, a low temperature laterally disposed superheater offset inthe superheater space adjacent the gas path and ahigh temperaturelongitudinally disposed superheater offset adjacent the furnace space,each such superheater including. a

pluralityof superheater tubes connected, as a group, ,at

a spaced point from the connection of the other superheater to theheader in generally parallel planes and at right angles to the header,the path of each tube being tortuous and including a zig-zag sectionwith laterally horizontal, rectilinear lengths and integral, connectingbends providing an over-all, generally rectangular outline, therectilinear lengths and integral connecting bends being alignedgenerally with the gas path and furnace space, respectively, to providea minimum resistance to the flow of hot gases through the superheaterspace into the gas path, a lateral Wall of circulation tubes generallyin the line of flow of hot gases from the furnace space ahead of thehigh temperature superheater, and a line of screen tubes across theentrance to the low temperature superheater.

References Cited in the file of this patent UNITED STATES PATENTSOstermann -4 Aug. 7, Kerr July 28, Stillman Apr. 30, Kerr Dec. 8,Stillman July 9, Andrew Feb. 4, Behr July 24,

FOREIGN PATENTS France June 17,

